CO对NH_(3)还原NO过程的影响与机理研究  

Study on the Characteristics and Mechanism of the Effect of CO on the Reduction of NO by NH_(3)

作　　者：舒淘 苏胜[1] 贾萌川 于娟[2] 张忠孝[2] 汪一[1] 胡松[1] 向军[1] SHU Tao;SU Sheng;JIA Mengchuan;YU Juan;ZHANG Zhongxiao;WANG Yi;HU Song;XIANG Jun(State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,China;School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]华中科技大学煤燃烧国家重点实验室,武汉430074 [2]上海交通大学机械与动力工程学院,上海200240

出　　处：《动力工程学报》2023年第10期1343-1351,1362,共10页Journal of Chinese Society of Power Engineering

基　　金：国家自然科学基金联合基金重点支持项目(U20A20321)。

摘　　要：为揭示CO对NH_(3)还原NO过程的影响,在不同CO体积分数下对NH_(3)还原NO过程进行了实验与模拟研究。实验结果表明:无氧气氛中存在CO时,对1400℃以下NO还原率无显著影响;CO可提高1400℃以上的NO还原率。在低氧体积分数条件下,CO的存在能扩展NH_(3)还原NO反应的温度窗口,使其在1400℃以上仍保持高NO还原率。在高氧体积分数条件下,CO仅使最佳脱硝温度向低温移动,并使脱硝温度窗口变窄。模拟结果表明:在无氧及低氧体积分数条件下,1400℃以上时CO可促进NH_(2)与CO反应生成HNCO,随后HNCO转化为NCO后将NO还原,增强了NO还原过程;高氧体积分数条件下,CO可在较低温度下促进OH、O等基团产生,保证NH_(2)生成及其还原NO过程进行;但温度升高会加快CO与OH反应产生H,H与O_(2)反应产生大量O,加速了NH_(2)氧化,导致NO还原率迅速降低。In order to reveal the effect of CO on the reduction of NO by NH_(3),experimental and simulation studies were carried out on the NO reduction process by NH_(3)at different CO concentrations.Results show that the addition of CO has no significant effect on the NO reduction efficiency below 1400℃under anaerobic conditions,and above 1400℃,the NO reduction efficiency of the NO reduction process by NH_(3)is improved when CO is present in the atmosphere.Under low O_(2)conditions,the temperature window of NO reduction by NH_(3)process is expanded under low oxygen concentration conditions when CO is present in the atmosphere.Thus,it can still maintain a higher NO reduction efficiency at a high temperature above 1400℃.Under the condition of higher O_(2)concentration,when CO is present in the atmosphere,the optimal NO reduction temperature moves to the low temperature,and the NO reduction temperature window narrows.The simulation results show that,under anaerobic and hypoxic conditions,above 1400℃,CO promotes the reaction of NH_(2)and CO to generate HNCO,and then HNCO further reacts with OH to generate NCO,and then reduces NO,thereby enhancing the NO reduction process.When the O_(2)concentration is high,the generation of OH and O is promoted by CO at a lower temperature,thus ensuring the progress of NH_(2)generation and NO reduction process.The temperature increase will accelerate the process of CO and OH reaction to generate H,then promote the reaction of H and O_(2),so that a large number of O radicals are generated in the reaction process,and these O radicals are easily oxidized with NH_(2).As a result,NO generation is promoted,resulting in a rapid decrease of NO reduction efficiency.

关 键 词：选择性非催化还原 NH_(3) NO还原率 CO体积分数 反应动力学 

分 类 号：X511[环境科学与工程—环境工程]